166665775 has 12 divisors (see below), whose sum is σ = 207404632. Its totient is φ = 132855840.

The previous prime is 166665767. The next prime is 166665781. The reversal of 166665775 is 577566661.

It is a happy number.

It is not a de Polignac number, because 166665775 - 2³ = 166665767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4704 + ... + 18853.

Almost surely, 2^166665775 is an apocalyptic number.

166665775 is a deficient number, since it is larger than the sum of its proper divisors (40738857).

166665775 is a wasteful number, since it uses less digits than its factorization.

166665775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23850 (or 23845 counting only the distinct ones).

The product of its digits is 1587600, while the sum is 49.

The square root of 166665775 is about 12909.9099532104. The cubic root of 166665775 is about 550.3202267412.

The spelling of 166665775 in words is "one hundred sixty-six million, six hundred sixty-five thousand, seven hundred seventy-five".